# 3D analysis with models obtained from 3D scans

**URL:** <https://discourse.slicer.org/t/3d-analysis-with-models-obtained-from-3d-scans/30004>\
**Category:** Support\
**Created:** [June 13, 2023, 8:38am UTC](https://discourse.slicer.org/t/3d-analysis-with-models-obtained-from-3d-scans/30004 "2023-06-13T08:38:18Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![IsabelW96](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/isabelw96/32/66474_2.png) [@IsabelW96](https://discourse.slicer.org/u/IsabelW96)\
**Post date:** [June 13, 2023, 8:38am UTC](https://discourse.slicer.org/t/3d-analysis-with-models-obtained-from-3d-scans/30004/1 "2023-06-13T08:38:19Z")

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Hello everyone,

Currently I am conducting research on the positioning accuracy of surgical guides on 3D printed bone models. I take a 3D scan of the bone models with the attached surgical guide, and I want to analyze this entire setup in comparison to a reference model.

I am fairly new to 3D Slicer, and I am working only with loaded STL files, which are the models.

The steps I want to perform are as follows:

1. Set up a coordinate system on the reference model.
2. Align the test model with the reference model.
3. Compare the translation and rotation of the surgical guide on the test model with those on the reference model.

Does anyone have any tips on the appropriate modules I can use?

Thank you in advance!

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**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [June 16, 2023, 2:33pm UTC](https://discourse.slicer.org/t/3d-analysis-with-models-obtained-from-3d-scans/30004/2 "2023-06-16T14:33:49Z")

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You can [align the models using registration](https://slicer.readthedocs.io/en/latest/user_guide/registration.html#model-registration) and compute basic translation/rotation properties using [Characterize transform matrix](https://github.com/PerkLab/SlicerSandbox#characterize-transform-matrix) module (provided by Sandbox extension).